DC RESISTIVITY OF CHARGED COOPER PAIRS IN A SIMPLE BOSON-FERMION MODEL OF SUPERCONDUCTORS

An analytic expression for the contribution σB(λ, T) to the conductivity from charged bosonic Cooper pairs (CPs) is derived via two-time Green function techniques as a function of the BCS interelectron interaction model parameter λ and temperature T. Within the framework of a binary boson-fermion gas mixture model, it is shown that a self-consistent description of the resistivity data observed in high-temperature superconductors is possible only by assuming the presence of a finite gap between the energy spectra of free fermions and bosonic CPs.